Diagnostic Test

WARNING: This page is about a different car, the 2009 Dodge Caliber. However, it is still accessible from the selected car via links, so may be relevant.

DTC IS ACTIVE
WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near any part of the exhaust system. The temperature rises to a high level after a short period of engine operating time.
1. Start the engine and allow it to reach normal operating temperature.
  WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
  
  NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Perform the CHECKING FOR AN INTERMITTENT DTC diagnostic procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K157) MAF SENSOR SIGNAL CIRCUIT VOLTAGE

Fig 1: Checking MAF Sensor Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C1 Secondary Air Pump Assembly harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K157) MAF Sensor Signal circuit in the C1 Secondary Air Pump Assembly harness connector.
  Is the voltage between 4.8 and 5.2 volts?
  
  Yes
  - Go to step 3
  No
  - Go to step 4
(K957) MAF SENSOR GROUND CIRCUIT TEST

Fig 2: Checking MAF Sensor Ground Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Using a 12 volt test light connected to 12 volts, check the (K957) MAF Sensor Ground circuit in the C1 Secondary Air Pump Assembly harness connector.
  NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go to step 8
  No
  - Go to step 7
(K157) MAF SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 3: Checking MAF Sensor Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Powertrain Control Module (PCM) harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K157) MAF Sensor Signal circuit in the C1 Secondary Air Pump Assembly harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K157) MAF Sensor Signal circuit for a short to voltage.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
(K157) MAF SENSOR SIGNAL CIRCUIT SHORTED TO THE (F343) FUSED ASD/MAIN RELAY OUTPUT CIRCUIT

Fig 4: Checking MAF Sensor Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Measure the resistance between the (K157) MAF Sensor Signal circuit and the (F343) Fused ASD/Main Relay Output in the C1 Secondary Air Pump Assembly harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the (K157) MAF Sensor Signal circuit for a short to the (F343) Fused ASD/Main Relay Output circuit.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 6
(K157) MAF SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 5: Checking MAF Sensor Signal Circuit
Courtesy of CHRYSLER LLC

CAUTION: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
1. Measure the resistance of the (K157) MAF Sensor Signal circuit between the C1 Secondary Air Pump Assembly harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 9
  No
  - Repair the (K157) MAF Sensor Signal for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K957) MAF SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 6: Checking MAF Sensor Ground Circuit
Courtesy of CHRYSLER LLC

CAUTION: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
1. Measure the resistance of the (K957) MAF Sensor Ground circuit between the C1 Secondary Air Pump Assembly harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 9
  No
  - Repair the (K957) MAF Sensor Ground circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
SECONDARY AIR PUMP ASSEMBLY
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Secondary Air Pump Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Refer to any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace the Secondary Air Pump Assembly in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Secondary Air Pump Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Refer to any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .